More Money Than Brains - a water cooled cab build

bicit

bicit

Well-Known Member
SomeGuy said:
to do dwc in a small space takes a rez with chiller outside that space. the heat is no bueno for the water in dwc. That is why it is a poor choice in cabinets. I have tried dwc and been hit or miss.... all because of water temps. passive hydro is cheap and fail proof.
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Would water temps not be an issue with either one since they both amount to a bucket of water with a plant in it? I've never used the hempy method, however I've been using DWC of various flavors for years. His setup seems ideal for keeping proper water temps without a chiller.
 
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churchhaze

Well-Known Member
[Almost] Everyone on rollitup.org underfeeds their plants!

It's one of the most common problems in the help section, but everyone steers them toward starving them more.

"Has being starved for most of her life has accelerated blooming?"

Calcium deficiency in particular will induce early senescence. I guess the other way of looking at it is that calcium sufficiency delays senescence.

Observe & Report said:
So it turns out I have been starving my plants! At my first feeding I gave them what I intended to be full strength Lucas (8ml FloraNova Bloom per gallon.) However, I thought my watering can was 1L but actually it was 0.5L so I gave the plants a double dose and burned them. I scaled it back to 1/4 dose and never upped it because the plants seemed to be growing. All the lower leaves would turn yellow and shrivel up but they kept growing.

So now I'm giving the flowering plants full strength FNB and I have picked up some Dyna-Gro Grow for the veggies. They didn't have the Foliage Pro and this is just a little bottle.

View attachment 3176774


With Lucas strength FNB, the yellowing stopped on the last fan leaf on my teeny little flowering plant and new fan leaves are sprouting out of the lower nodes again.

Has being starved for most of her life has accelerated blooming? Below is a crop of the above shot at 40 days. It should be way too early but already almost all trichs appear cloudy and some are becoming oxidized. The shot from last week shows no amber trichs. Judging by trichomes would you say this is ready, because I like to get high not stoned, but surely it will keep going?

View attachment 3176776
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Red1966

Red1966

Well-Known Member
Observe & Report said:
I rigged up the fan on the radiator so now I can turn on the flowering lights and see whats going on. I'm still using the ordinary pump without fan controller but the fan has a low/high switch. At low you can only barely hear it if you stick your ear right up to it and I have to feel the breeze to be sure it's on. At high (full 12V) it makes a whoosh sound that is louder than I'd like. It's a 120mm Antec TrueQuiet Pro.

I turned all of the lights in all three compartments on full blast and let the temperature stabilize after a couple hours. I'm measuring the temp of the water in the coolant reservoir. With the fan on low the coolant temp is 42C (107F) once the system reaches equilibrium. With the fan on high the coolant is almost 38C (100F).

View attachment 3010554

I tried to measure Tc with a really crappy infrared thermometer right after turning off the light. It was about 46C when the coolant was 38C. So I'm closer to 50C than 25C, probably 60C, but my lighting system is almost silent and most of the heat is removed from the cab without any additional noise and none of that noise is in or near the cabinet. The cooling system consumes 5.3W right now. I'm confident the new pump will be even more quiet but it is going to require a good long burn in period in a bucket before installation for me to trust it. The case has room for another radiator. Another radiator at $75 can pay itself off in 3 years or so if it provides 3% more light. The cooling system wont go obsolete like the COBs.

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I rigged up a stand for the sensor on an Apogee QMSS-E and took some measurements. I got this when Apogee discontinued this model and it hasn't been calibrated since it was made. I did take it outside at noon on a clear day and compared the reading to the expected value off Apogee's website and it was pretty close but it jumped around because I wasn't using a stand for the sensor. Also, this thing is calibrated for "electric light" but not for these LEDs so the value could be off by 10% or more. I think it's in the ballpark but don't take these numbers as gospel.

PAR-tay at my place!

View attachment 3010556

I measured 1/4th of the flowering compartment from 12" and 18" below the COB, that's about 12.75" below the ceiling. Since it's symmetrical, I expect almost identical readings on the other three sides. Taking these readings is a PITA. I used a tape measure to try to be reasonably accurate, but these numbers are just for entertainment purposes.

drumroll please....

View attachment 3010557 View attachment 3010558

I put the Angelina-W reflector on the center light but at 12" it overloaded the meter! Well over 2000 umol/m/s in the dead center. However, it dropped from 950 without to 750 with reflector halfway to the wall in the center. So the reflectors are good if you want to put the lights further away than 12" (i.e. you want a lot of penetration.)


It looks like I got a pretty sick lighting system in my flowering compartment, what do you think?
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Kudos. Great job.
 
dr.medecine

dr.medecine

Well-Known Member
Very cool, have had the same idea myself but never got to it really. Perhaps now is the time seeing up to 30c in the small tent I have (summer here) so gotta run AC in the apartment but it ruin the hole idea of efficient buying imho, I have a chiller as well as a few old EK blocks + a Laying DDC laying around here so maybe I should try?

Would prefer a rad though cause the chiller want juice from the wall although not as much as the AC unit though. Is the rad working alright for you when really hot inside?
 
Observe & Report

Observe & Report

Well-Known Member
The hotter it gets inside then the hotter your coolant will be because the efficiency of the radiator is related to the difference in temperature between the coolant and the air flowing through it. Probably Fourier's law again, vital if you're an LED hacker.
 
Observe & Report

Observe & Report

Well-Known Member
I'm still battling heat. Part of it is the temperature of the loop/blocks, they are like little heaters in the box and increasing radiator area or airflow would reduce that some. I think most of the heat is radiating off the front of the emitters though. You can feel the heat when you put your hands underneath. I had black gaffers tape wrapped around the pots and the medium temp was 90F. Putting reflective silver tape over that dropped the medium temp to 85F.

I think the root of the problem may be that I'm just pumping a lot of light into a small space (1100-1200 umol @ 12" in a line down the center) with nothing to soak it up because I just have a couple of little runt plants in there. People who say LEDs "dont generate heat" probably don't have very brightly lit rooms.

I'm contemplating adding 2-3 more '29s and driving them all at 1A instead of 1.88A I don't know how much it will reduce the temperature in my cabinet if at all. i.e. if a lot of heat is just from the light streaming out, then having the same total irradiance generated at a lower current might not make much impact in the temperature of the cabinet. or will it? Less heat will go out the back but what about the front? Maybe an expert can chime in on this one. It could be that I'm just overdoing the light (Too Much Of Everything Is Just Enough...)
 
epicfail

epicfail

Well-Known Member
I don't know if you mentioned what exhaust fan your using but I used to use a fan similar to this, it was effective but loud; even when slowed it down you could always hear it. I ordered up a TD-Silent fan and when I plugged it in my partner immediately ordered a second. They can be wired in high or low speed, low speed is all I ever use and its super quiet. My tent actually runs 1-2 degrees cooler than ambient most of the time with a cheap 6" carbon filter. The old one was like a jet turbine but it was needed with the glass sodium sun that used to hang in there.
 
Observe & Report

Observe & Report

Well-Known Member
Yes, I'm using a S&P TD-Silent, the smallest 4". It's pretty quiet dialed down at 50%, certainly quieter than the server in the same closet, but quieter is always better. I need to try running it flat out, just to see if increasing fan power will do the trick.
 
epicfail

epicfail

Well-Known Member
Observe & Report said:
Yes, I'm using a S&P TD-Silent, the smallest 4". It's pretty quiet dialed down at 50%, certainly quieter than the server in the same closet, but quieter is always better. I need to try running it flat out, just to see if increasing fan power will do the trick.
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When I was researching the fan I read that the 4" inch model was the loudest, smaller motor = higher pitch and easier to hear. I bought the 6" versions as it was supposed to be noticeably quieter. Also I found when I it up to a fan controller it was also about 1.5-2x, the triac dimmer was creating a buzz. I found that instead of dialing it down I just wired it to the low speed setting and it was much quieter, it was even quieter on full when bypassing the fan dimmer. With it plugged into the dimmer I could hear the fan from the next room, looking into a variac dimmer will remove the buzz but a 5A one is like 125$. I was thinking getting a small VFD (cheaper then a Variac) and controlling speed with an arduino through pwm, or just building a thermostat controller that will switch the fan from high to low so there is no change of motor noise.

I hope there are some suggestions that help.

On another note O&R, you inspired me to try something different. I took a 1x2" length of aluminum tubing, welded the ends shut and tapped them with a 1/4 NPT tap. I'm not a good welder (I suck actually) but I managed to get it water tight. It is a custom 14" long aluminum water block designed for 2 two CXA3070's that I will hook up to my old Zalman Reserator (mine is blue not black). I don't know if it will handle the wattage but it wont hurt to try.

waterblock1.JPG waterblock2.JPG​
 
Observe & Report

Observe & Report

Well-Known Member
Yeah I'm just using the low/high settings on the fan but I also have some special doodad that S&P recommends that drops the power in half again. The fan is almost silent when run on low with the doodad inline, I'd really like to get it to where I can run like that. Before spending hundreds on new fans or more cobs/drivers/blocks/fittings/radiators I need to double down on my duct work. I need to ensure the air going into the cab is cool. First by snaking duct around the side of the cab to the front so it can pull air from outside the closet. It is against a side of the closet with a few inches of clearance. The doors are sliding and that side of the closet is obscured behind the open door to the room, so I can leave the closed door open for cool air to get in. I might have to locate the exhaust/filter outside the closet too instead of relying on doors being open. Nothing is ever simple.

Meanwhile my plants are vegging so slowly. Partially because the one female I have right now was the runt of the litter and grows slowly and also because I've been having PH problems that I recently got sorted out.


Those water blocks look great! I wish I could get some nice long ones for spreading out the smaller COBs. and the radiator... Super nice!
 
Observe & Report

Observe & Report

Well-Known Member
The flowering chamber is 235W + 5W cooling at the wall at full power. I have it turned down a bit to keep the temps in the low 80's. I'll measure how much wattage I'm drawing and report back after the weekend.

A good carbon filter on the exhaust takes care of odor. Carbon doesn't remove every chemical emitted by the plants but it removes the weed smell. On my setup the residual smell is very faint and reminds me of drunk breath. I'm especially sensitive though. Also, I haven't been flowering heavily yet with a stinky strain. Right now there are only a few small plants in there under 4 weeks along and they don't smell too much unless you rub them. The green leaves and stems of the Time Wreck are pretty skunky though. If I leave the doors open or hook up the fan in reverse then the room smells skunky.
 
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DarthBlazeAnthony

Well-Known Member
MrFlux said:
When the plants get bigger the temperature will drop due to increased evaporation. My cooling strategy is to keep a large plant mass that can keep itself cool.
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That is interesting. I had not heard that before. Do you prefer to grow one big ass plant rather than 3 decent size ones?
 
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grouch

Well-Known Member
Observe & Report said:
Those water blocks look great! I wish I could get some nice long ones for spreading out the smaller COBs. and the radiator... Super nice!
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Have you looked into the aluminum blocks they use in bars and soda machines to chill the liquids at the bottom of the ice bin? I think they come in a variety of sizes.
 
MrFlux

MrFlux

Well-Known Member
DarthBlazeAnthony said:
That is interesting. I had not heard that before. Do you prefer to grow one big ass plant rather than 3 decent size ones?
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I noticed that with the warmer weather the temperature of my plants remained the same, they only needed more water. In my case over half of the heat is transported away as water vapor.

I prefer more plants but it would work for a large tree as well, it's probably the total leaf surface area that counts.
 
Observe & Report

Observe & Report

Well-Known Member
I've been keeping the lights turned down and soon the flowering chamber will be more full so I don't think heat will be any issue anymore. The weather has been warm and the room that the cab is located in has been pretty warm too. @stardustsailor posted some interesting info regarding diminishing returns with really bright lights so I'll keep them turned down until I know I need more yield.

These two TGA Time Wrecks have been vegging for 7.5 weeks and are getting pretty close to flipping. The left one has maybe a week. I've been really worried about stretch but this cut doesn't seem to stretch much and I think i have plenty of vertical room with these low profile buckets so I'm probably going to fill the screen before flipping. These grow slowly but part of it has been me figuring out how to grow.

pic-2.jpg


These little ladies below were cut at the same time as the scroggers above. They are in much smaller buckets. I have no idea how big these things will get or how much room I have so I've been experimenting. So far they are all way too small! They could be three times bigger.

The far right one was vegged for 3 weeks and is at day 32 of flower, left one vegged for 4 weeks and is at day 25, and middle vegged for 5 weeks and is at day 19. They grow so slowly but they also didn't have a happy 4th of july. Overheated, underwatered, under fertilized. They have recovered though. The far right one will probably finish fast again.

pic-1.jpg



TGA Time Wreck day 32 under around 950-1000 umol/-s/m-2 of 4000K Vero 29's Pistils going brown and some trichs are amber, dunno if this is a freak that finishes fast or just the abuse.

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Got a few more cuts of the Time Wreck plus five Mr. Nice Critical Widows at day 46 from seed. There are also five TGA Querkles at about a week since they broke ground.


pic-3.jpg


Some day, some day.... I can't believe how long this is taking, I planted seeds on like Feb 19.
 
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